1. Technical Field
The invention relates to circuit devices, electronic apparatuses and power supply circuits.
2. Related Art
Adiabatic logic circuits are known as a technology to suppress power consumption of logic circuits (for example, the technology described in JP-A-2002-325031). The adiabatic logic circuit suppresses power consumption, which may be caused by the drain loss of transistors, by changing the power supply voltage. Also, a adiabatic logic circuit formed from CMOS static logic gates without using diodes, and a switched capacitor circuit that generates power supply clocks (for example, the technology described in JP-A-2009-278433) are known.
When diodes are used in an adiabatic logic circuit, the power consumed by the diodes cannot be ignored. While power supply voltages have been lowered due to the progress in miniaturization of semiconductor manufacturing process, voltage drops caused by diodes lower the voltage level of signals, and deteriorate the degree of noise margin. In this respect, the adiabatic circuit system without using diodes, described in JP-A-2009-278433, has been proposed.
However, when the power supply circuit that supplies power supply voltages to the adiabatic logic circuit does not perform power regeneration, the power consumption cannot be sufficiently suppressed. In other words, the energy of charges returned to the power supply circuit from the adiabatic logic circuit is consumed without being regenerated at the power supply circuit, whereby the power consumption in the power supply circuit increases.
In this connection, the inventor of the present application has developed a technique that uses a resonant circuit formed with two independent coils and a capacitor as a power supply circuit, and performs power regeneration by the resonance circuit, as will be described below with reference to a comparison example.
However, this technique requires two coils as parts externally installed to the power supply LSI, and thus entails a problem in that the mounting area increases. For example, to maintain the resonance against power loss in the adiabatic logic circuit, it is necessary to have two coils with high Q value which occupy about the same mounting area as that of the LSI and the like formed from the logic circuit including the power supply circuit.